Science Seminars

Subsurface Ocean Detection in Icy Worlds Using Magnetic Induction

Speaker: Corey Cochrane (JPL)
Date: Thursday, Apr 28, 2022
Time: 4:00 PM
Location: Zoom

Seminar Abstract:

Many moons in the solar system are thought to potentially harbor hidden oceans based on the features observed at their surfaces. However, the best evidence for the existence of subsurface oceans arises from interpretation of magnetic field measurements collected by the magnetometer on the Galileo spacecraft in the vicinity of Europa and Callisto. The putative salty oceans within these moons are able to conduct electrical currents that are driven by Jupiter’s strong time-varying magnetic field, producing a unique secondary magnetic field signature that can be measured externally by as spacecraft. Some of the large moons of Uranus and Neptune are also thought to possibly contain subsurface oceans. Unfortunately, Voyager 2 did not pass close enough to any of them for its onboard magnetometer to sense the field signatures associated with a conductive ocean.
In this presentation, an explanation of how the magnetic environments of Jupiter, Uranus, Neptune, and surprisingly Saturn, provide ideal magnetic conditions to facilitate magnetic induction studies of their moon’s interiors. The concept of magnetic induction will be explained and how it can be used to detect and characterize subsurface oceans within the icy bodies of the solar system for single- or multi-flyby mission concepts. Also presented will be the feasibility of detecting magnetic induction signatures of subsurface oceans within the moons of Ice Giants based upon various assumed interior profiles, thus providing guidance to required magnetometer performance and trajectory design for possible future mission concepts to these systems.